Rainbow Obsidian from Mexico.
PUMI1999
Obsidian is formed by the rapid cooling of viscous lava that is extremely rich in silica. It has no crystal structure as it cools too fast to crystallise, a stone similar to a natural glass. Those rainbow colors are caused by pyroxene's nanoparticle inclusions in the hot lava. More especially, particles of Hedenbergite. When polishing a piece of this Mexican stone, we sometimes discover those lustrous layers... Volcano Tequila, mine of La Revoltosa in Jalisco state.
This unique piece has been sold...
